Google uses confirmation messages from Gmail to show helpful information about your purchases in Google Now, Google Search and other Google services. That's not a new feature, but there are some ways to make it even more useful.
If you're signed in to your Google account, you can search for [my purchases] and Google shows your latest purchases from sites like Amazon, eBay, Google Play and more. Click one of the items to find more details, including tracking links, prices and links to email receipts. Click "show 10 more results" to see more orders.
Read the full post @ the Google Operating System blog.